Our bootstrapping setup compiles multiple versions of the generated code for `descriptor.proto` and `plugin.proto`, one for each stage of the bootstrap. For source files (`.c`), we can always select the correct version of the file in the BUILD rules, but for header files we need to make sure the correct stage's file is always selected via `#include`.
Previously we used `cc_library(includes=[])` to make it appear as though our bootstrapped headers had the same names as the "real" headers. This allowed a lot of the code to be agnostic to whether a bootstrap header was being used, which simplified things because we did not have to change the code performing the `#include`.
Unfortunately, due to build system limitations, this sometimes led to the incorrect header getting included. This should not have been possible, because we had a clean BUILD graph that should have removed all ambiguity about which header should be available. But in non-sandboxed builds, the compiler was able to find headers that were not actually in `deps=[]`, and worse it preferred those headers over the headers that actually were in `deps=[]`. This led to unintended results and errors about layering check violations.
This CL fixes the problem by removing all use of `includes=[]`. We now spell a full pathname to all bootstrap headers, so this class of errors is no longer possible. Unfortunately this adds some complexity, as we have to hard-code these full paths in several places.
A nice improvement in this CL is that `bootstrap_upb_proto_library()` can now only be used for bootstrapping; it only exposes the `descriptor_bootstrap.h` / `plugin_bootstrap.h` files. Anyone wanting to use the normal `net/proto2/proto/descriptor.upb.h` file should depend on `//net/proto2/proto:descriptor_upb_c_proto` target instead.
PiperOrigin-RevId: 664953196
This is needed to make protobuf/bazel package minimal for other proto rules.
Keep 4 public bzl files in upb/bazel. They end up under protobuf/bazel, and they are legitimately used by other repositories.
Move upb_proto_library_internal/* under bazel/private. Those are utilities used in the rules. Moving them one level deeper makes protobuf/bazel package clean for other rules.
Move build_defs.bzl and amalgamation under /upb/bazel. Those are utilities used in the build.
Move lua.BUILD and python* uner /python/dist. Those are used in the WORKSPACE dependency setup.
PiperOrigin-RevId: 621442236
This makes third_party/utf8_range no longer a Git subtree, but instead the
permanent location and source of truth for utf8_range. It is also now
incorporated into the @com_google_protobuf Bazel repo. Utf8_range still has its
own separate CMake build for now, though.
PiperOrigin-RevId: 580682733